The phrase "more low down" can be used to describe something that is secretive or hidden. Some synonyms for this phrase could be "more obscure," "more concealed," or "more covert." Other possible options might include "more clandestine," "more surreptitious," or "more furtive." These words all suggest that something is hidden or kept from public view, whether intentionally or not. Depending on the context, other synonyms could include "more recondite," "more enigmatic," or "more inscrutable," which all imply a certain level of complexity or mystery. Overall, there are many different synonyms that can be used to convey the idea of something being "more low down".